Process for preparing 1, 1, 1, 2, 2-pentafluoro-3-chloropropane and 1, 1, 1, 2, 2-pentafluoro-3-bromopropane



United States Patent PROCESS FOR PREPARING 1,1,1,2,2-PENTAFLUO- R0 3CHLOROPROPANE AND 1,1,1,2,2 PEN- TAFLUOR0-3-BROMOPROPANE Max M.Boudakian, Hamden, New Haven, Conn., as-

signor to E. R. Squibb & Sons, Inc., New York, N.Y., a corporation ofDelaware No Drawing. Filed Feb. 18, 1966, Ser. No. 528,356

3 Claims. (Cl. 260653) ABSTRACT OF THE DISCLOSURE CF CF CH X, wherein Xis chlorine or bromine, is prepared by treating a compound of theformula wherein X is chlorine or bromine and Y is any halogen, with adisproportionate catalyst.

This invention relates to a new process for preparing the compounds: CFCF CH Cl and CF CF CH Br.

The process of this invention in its broadest aspects entails treating acompound of the formula wherein X is chlorine or bromine, and Y is anyhalogen, with a disproportionation catalyst to yield a compound of theformula CF CF CH X, wherein X is as hereinbefore defined.

Among the suitable catalyst may be mentioned aluminum bromide, aluminumfluoride, boron trifiuoride or its etherate, ferric chloride, ferricbromide, antimony trichloride, antimony pentachloride, tintetrachloride, titanium tetrachloride, zinc chloride, and preferablyaluminum chloride. The catalyst can be present in any amount andpreferably is present in a concentration in the range of about 0.01 toabout 25 percent by weight, and optimally about 1 to about percent byweight.

The reaction can be carried out at any normal temperature, andtemperatures in the range of about C., to about 450 C. are utilizable.Preferably the temperature is in the range of about 0 C. to about 100 C.Under these conditions the desired reaction is achieved in a reactiontime of about 1 minute to about 24 hours.

Among the suitable halogenated hydrocarbon reactants can be mentioned:CI CFCF CH CI; ClCF CF CH Cl;

CBr FCFgcH Br; and CBrF CF CH Br, and mixtures thereof.

The following examples illustrate the invention (all temperatures beingin centigrade):

EXAMPLE 1.CF CF CH Cl I (a) Preparation of ClCF CF CH Cl and Cl CFCF CHCl Mercuric oxide (15.1 g.; 0.07 mole), hydrogen fluoride (16.8 g.; 0.84mole) and CCl CF CH Cl (0.07 mole; 15.4 g.; 96.1% assay) are heated in a150 ml. Monel cylinder for 7 hours at -138 (175 p.S.i.g., maximumpressure) with agitation. The residual pressure is 20 p.s.i.g. (roomtemperature). The cylinder is cooled to 0 and the volatiles are passedinto 200 ml. 10% sodium hydroxide (0). The contents of the cylinder arecombined With 50 g. cracked ice. The combined aqueous layers (pH 11) aresteam-distilled. From 600 ml. steam-distillate, about 7.2 g. of an oillayer, n 1.3644 is collected. The product consists of two components: CFClCF CH C1 and CCl FCF CH Cl separated by preparative VPC.

(b) Preparation of CF CF CH Cl A mixture containing 3.87 g. CCl FCF CHCl (45%) and CF C1CF CH Cl (51%) and aluminum chloride (0.45 g.) arestirred at room temperature for 15 hours and at 60-65 C. for 4.5 hours.The reaction product is cooled to 0 and 25 g. water (0 C.) is added. Theorganic layer is separated and found to contain CF CF CH Cl by vaporphase chromatography. The presence of CF CF CH Cl is confirmed byspiking the product With an authentic sample of CF CF CH CI.

- EXAMPLE 2.CF CF CH Br Following the procedure of Example 1, butsubstituting an equivalent amount of CBr CF CH Br for the in (a),CF3CF2CH2BI' is obtained.

The invention may be variously otherwise embodied within the scope ofthe appended claims.

What is claimed is:

1. A process for preparing a compound of the formula CF CF CH X, whereinX is selected from the group consisting of chlorine and bromine, whichcomprises treating a compound of the formula CFXYCF CH X, wherein Y isany halogen and X is as hereinbefore defined, at a temperature of about0 C. to about C., with a catalyst selected from the group consisting ofaluminum chloride, aluminum bromide, aluminum fluoride, borontrifiuoride, the etherate of boron trifluoride, ferric chloride, ferricbromide, antimony trichloride, antimony pentachloride, tintetrachloride, titanium tetrachloride and zinc chloride.

2. The process of claim 1 wherein the halogenated hydrocarbon is amixture of CFCl CF CH Cl and UNITED STATES PATENTS 8/1949 Miller et a1.260653 5/ 1952 Miller et al.

DANIEL D. HORWITZ, Primary Examiner.

